Tetralysal Mechanism of Action

Pharmacology: Pharmacodynamics: Lymecycline is an antibiotic belonging to the tetracycline family (group of the semi-synthetic cyclines).
Antibacterial activity: The natural antibacterial spectrum of lymecycline is that of cyclines: Sensitive species: Brucella, Pasteurella, Chlamydiae, Propionibacterium acnes, Gonococci, Haemophilus, Leptospira, Mycoplasma, Pneumoniae, Ureaplasma urealyticum, Rickettsiae, Treponema pallidum, Vibrio cholerae.
Species with variable sensitivity (10 to 40% resistant strains): Anaerobic organism (Clostridium, Bacteroides, Fusobacterium), Escherichia coli, Klebsiella, Legionella pneumophila, Pneumococci, Proteus morganii, Shigella, staphylococci, streptococci, streptococci groups A, C and G.
Resistant species (MIC ≥ 16 mg/L): Enterobacter, Mycobacterium tuberculosis, Proteus rettgeri, Providencia, Pseudomonas, Serratia, Streptococci groups B and D.
Effects on acne: The exact mechanisms by which tetracyclines reduce lesions of acne vulgaris have not been fully elucidated; however, the effect appears to result in part from the antibacterial activity of the drugs. Following oral administration, the drugs inhibit the growth of susceptible organisms (mainly Propionibacterium acnes) on the surface of the skin and reduce the concentration of free fatty acids in sebum. The reduction in free fatty acids in sebum may be an indirect result of the inhibition of lipase-producing organisms which convert triglycerides into free fatty acids or may be a direct result of interference with lipase production in these organisms. Free fatty acids are comedogenic and are believed to be a possible cause of the inflammatory lesions, e.g. papules, pustules, nodules, cysts, of acne. However, other mechanisms also appear to be involved because clinical improvement of acne vulgaris with oral tetracycline therapy does not necessarily correspond with a reduction in the bacterial flora of the skin or a decrease in the free fatty acid content of sebum.
Pharmacokinetics: Absorption: Absorption is rapid. Effective plasma levels are reached within the first hour following drug intake. The peak plasma level is reached within 3 to 4 hours after oral administration. Concurrent food intake, milk in particular, does not significantly modify the absorption of lymecycline.
Distribution: Oral administration of 300 mg, in the adult, gives rise to: a peak plasma level of 1.6 to 4 μg/mL; a highly variable residual concentration (0.29 to 2.19 μg/mL); a plasma half-life of approximately 10 hours.
Repeated administration results in a steady mean plasma concentration between 2.3 and 5.8 μg/ml. Wide intra and extra-cellular diffusion, under normal dosage conditions, results in effective concentrations in most body tissues and fluids, and notably in the lungs, bones, muscles, liver, bladder, prostate, bile and urine.
Excretion/elimination: The product is principally excreted in urine and secondarily in the bile. About 65% of the administered dose is eliminated within 48 hours.